1. Field of the Invention
The present invention relates to a Point of Interest (POI) icon display method and a navigation system for displaying a POI icon at a POI position on a map, and more particularly, to a POI icon display method and a navigation system for displaying a specified category of POI by the same POI icon among the POIs and enabling a type of the POI in the specified category to be identified.
2. Description of the Related Art
An on-vehicle navigation system detects a vehicle position and reads out map data for the area around the vehicle position from a map storage medium such as a CD-ROM or a DVD. Thereafter, a map and a guide route are drawn on a display picture plane (display screen), and a vehicle position mark is overlapped and drawn on a predetermined position on the map. In accordance with the change of the present position due to the movement of the vehicle, the vehicle position mark on the picture plane is moved along a guide route. Alternatively, the vehicle position mark is fixed at a predetermined position and the map is scrolled so that a user can understand a detailed map around the vehicle position with a single glance.
The navigation system includes a function for displaying icons (POI icons) indicative of different categories of POIs, such as an ATM (Automatic Teller Machine), bank, gas station, restaurant, hotel, car park, etc. on a map. Some POI categories can be further differentiated by type within the category. For example, there are various types of restaurant POIs. As a result, inconveniently, it is difficult to discriminate the type of food in a restaurant, namely, the type of food classified by country such as Japanese food, Chinese food, Italian food, and French food. It has been considered to use a different POI icon corresponding to each type of food. However, the number of icon types is increased and it may be difficult to have the POI icon correspond to the type of food.
A road may be congested with the POI icons in a display of a downtown area, as shown by A, B, C, and D in FIG. 11. Moreover, if a wide area view is employed, and the icon size displayed remains the same, icon density increases, and the road is further congested with a larger number of POI icons. In this situation, if moving a cross cursor onto the road in order to confirm a road name and an address on the map or to set a destination on the road, it is difficult to avoid selecting a POI icon and this prevents a road or a point on a road from being selected. Therefore, a problem arises that the user cannot confirm the road name and address or the setting of the destination, and the road name and the address must be confirmed and the destination must be set only after executing a complicated operation to erase the icons through a set-up menu.
The number of POI icons displayed on the map is increased in a downtown area, and a plurality of the same POI icons may be included within a cursor of a predetermined size. In such a case, a problem arises to make it difficult to input a point and select a road correctly.